Feropur

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

When in contact with water, the constituents of Feropur will be degraded within seconds to Na⁺,OH^-and H₂. Consequently, Na₂O and NaH are considered to be too short-living and hence irrelevant for the assessment of environmental and toxicological effects. Based on the very quick and complete degradation of Na₂O and NaH to NaOH, the risk assessments for the environment and humans are based on the properties of NaOH and Na₂CO₃.

This approach was discussed with ECHA (see attached document: "Strategy paper Feropur ECHA 090813.pdf"). ECHA agreed on this approach (see attached document "reply ECHA 090902.pdf").

The hazards of NaOH and Na₂CO₃ for the environment are caused by the hydroxyl ion and carbonate ion, respectively, and hence by an effect on the pH, i.e., both ions will increase the pH. However, the impact on the pH-effect of the carbonate ion is much weaker than the impact of the hydroxyl ion. In the SIDS dossier of sodium carbonate (SIDS dossier for sodium carbonate, 2002, Table 1, page 10, see attached document) it is outlined that 603 mg sodium carbonate/L are needed to increase the pH of distilled water to a pH of 11. To cause the same effect with sodium hydroxide, only 40 mg sodium hydroxide/L is needed (SIDS dossier for sodium hydroxide, 2002, Table 1, page 10, see attached document). Hence, the effects of sodium carbonate are about 15 times weaker than for sodium hydroxide. In addition, the concentration of sodium carbonate is only about 5% in Feropur. When in contact with water, the degradation products consists to about 95 % of sodium hydroxide and about 5% of sodium carbonate (see attached document "Strategy paper Feropur ECHA 090813.pdf"). When multiplying the concentration with the efficiency of sodium carbonate relative to sodium hydroxide (1/15th), i.e., 5%*1/15, the impact of sodium carbonate in Feropur would be about 0.3% when compared to the effect of sodium hydroxide in Feropur. Na₂CO₃ is registered as food additive E500i and may be added quantum satis to food and is therefore considered to be a substance of “low priority".

Based on the same mode of action and the much weaker effect of sodium carbonate in combination with the much lower content of sodium carbonate in Feropur when compared to sodium hydroxide, it can be concluded that the risk of Feropur is sufficiently described by the risk resulting from sodium hydroxide alone.

 

Data on skin sensitization for NaOH were reported by Park et al (1995) (EU RAR, 2007; section 4.1.2.4, page 70). Male volunteers were exposed on the back to sodium hydroxide concentrations of 0.063-1.0% (induction). After 7 days the volunteers were challenged to a concentration of 0.125%. The irritant response correlated well with the concentration of NaOH, but an increased response was not observed when the previously patch tested sites were re-challenged.

Furthermore, NaOH has been used widely and for long time and no human cases of skin sensitisation have been reported and therefore NaOH is not considered to be a skin sensitiser (EU RAR 2007).

This classification is also used for Feropur.

Migrated from Short description of key information:
Feropur has no skin sensitization potential

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

When in contact with water, the constituents of Feropur will be degraded within seconds to Na⁺,OH^-and H₂. Consequently, Na₂O and NaH are considered to be too short-living and hence irrelevant for the assessment of environmental and toxicological effects. Based on the very quick and complete degradation of Na₂O and NaH to NaOH, the risk assessments for the environment and humans are based on the properties of NaOH and Na₂CO₃.

This approach was discussed with ECHA (see attached document: "Strategy paper Feropur ECHA 090813.pdf"). ECHA agreed on this approach (see attached document "reply ECHA 090902.pdf").

The hazards of NaOH and Na₂CO₃ for the environment are caused by the hydroxyl ion and carbonate ion, respectively, and hence by an effect on the pH, i.e., both ions will increase the pH. However, the impact on the pH-effect of the carbonate ion is much weaker than the impact of the hydroxyl ion. In the SIDS dossier of sodium carbonate (SIDS dossier for sodium carbonate, 2002, Table 1, page 10, see attached document) it is outlined that 603 mg sodium carbonate/L are needed to increase the pH of distilled water to a pH of 11. To cause the same effect with sodium hydroxide, only 40 mg sodium hydroxide/L is needed (SIDS dossier for sodium hydroxide, 2002, Table 1, page 10, see attached document). Hence, the effects of sodium carbonate are about 15 times weaker than for sodium hydroxide. In addition, the concentration of sodium carbonate is only about 5% in Feropur. When in contact with water, the degradation products consists to about 95 % of sodium hydroxide and about 5% of sodium carbonate (see attached document "Strategy paper Feropur ECHA 090813.pdf"). When multiplying the concentration with the efficiency of sodium carbonate relative to sodium hydroxide (1/15th), i.e., 5%*1/15, the impact of sodium carbonate in Feropur would be about 0.3% when compared to the effect of sodium hydroxide in Feropur. Na₂CO₃ is registered as food additive E500i and may be added quantum satis to food and is therefore considered to be a substance of “low priority".

Based on the same mode of action and the much weaker effect of sodium carbonate in combination with the much lower content of sodium carbonate in Feropur when compared to sodium hydroxide, it can be concluded that the risk of Feropur is sufficiently described by the risk resulting from sodium hydroxide alone.

Justification for classification or non-classification

Existing data do not demonstrate that NaOH is a sensitizer.

Therefore, Feropur is considered to be not sensitizing.